Clinton still leads her competition with 40 percent versus Trump's 38 percent, according to a poll from The Economist/YouGov collected between Sunday and Monday. The web-based interviews of 1,300 general population respondents had a margin of error of 3.9 percent.

Despite Democratic presidential candidates taking both New Hampshire and Nevada in recent elections, recent Wall Street Journal/NBC News/Marist polls found that Clinton was only leading Trump by one percentage point in those states. The GOP nominee, however, was having trouble in traditionally Republican states like Arizona and Georgia, where he was leading 42 percent to 41 percent and 46 percent to 43 percent, respectively.